Federal officials hit back this week at Mayor Rahm Emanuel's attempt to block President Donald Trump's Justice Department from withholding grant money from sanctuary cities, saying they want only "modest cooperation" from Chicago and other cities in "the removal of aliens who have committed crimes."

In a federal court filing Thursday, the Justice Department urged a judge to reject Chicago's request to stop new rules for the distribution of Edward Byrne Memorial Justice Assistance Grants.

The city filed a suit this month arguing it's unlawful and unconstitutional for Attorney General Jeff Sessions to make the grants contingent on cities sharing information about a person's immigration status with federal officials enforcing deportation laws, providing unlimited police station access to those officials and giving the officials 48 hours' notice of an arrested person's release in cases of potential immigration violations.

And more broadly, the city argued the federal government isn't allowed to impose substantive conditions on cities applying for the Byrne grants.

With applications for Byrne grants due Sept. 5, the city also asked U.S. District Judge Harry Leinenweber to prevent Sessions' new rules from taking effect.

Federal lawyers countered that imposing the new regulations is well within their powers. In their motion, they said Chicago's position would "allow the city, not the department, to determine the conditions associated with a federal grant that Congress has authorized the department to award."

As expected, the city filed a motion Thursday with U.S. District Judge Harry Leinenweber, requesting an injunction....

(John Byrne)

And the filing says federal law lets the Department of Justice put conditions on the Byrne grant money. The city, it says, "ignores the close relationship between the federally-imposed conditions and federal law enforcement prerogatives."

And the motion says there's no need for an injunction to stop the requirements from being applied, because the city would have 45 days after being awarded a Byrne grant for next year to decide whether it wanted to accept the standards in order to get the money.

Mayoral spokeswoman Shannon Breymaier on Friday called on the Trump administration to stop defending the new rules.

"The Trump administration should immediately drop these new conditions on the Byrne grants, rather than try to salvage its ill-conceived and unlawful attempt to force cities to choose between critical funding for our community policing efforts and our values as a welcoming city," Breymaier said in an email.

The Byrne grant accounts for just a tiny part of this year's city budget, the $3.2 million slated to be used to purchase new police squad cars and new crime-fighting technology. But for Emanuel, the fight over the funding also gives him an opportunity to raise his profile in the ranks of big-city mayors who have opposed Trump's immigration policies. In a city like Chicago, which is heavily Democratic and has a large immigrant population, such stands can have long-term political benefits.